<!DOCTYPE html>
<html lang="zh-CN">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    // 使用 let 声明变量更加安全
    let str1 = '班长'


    let str1 = '组长'
    console.log(str1);
  </script>
</body>
</html>